controller with error handling

.gitignore

@@ -4,6 +4,9 @@
 *.so
 *.dylib
 
+# monitor binary
+gomon_spawn
+
 # Test binary, build with `go test -c`
 *.test
 
@@ -11,4 +14,4 @@
 *.out
 
 # Project-local glide cache, RE: https://github.com/Masterminds/glide/issues/736
-.glide/
+.glide/

backend/server.go

@@ -0,0 +1,61 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+const validNumberOfURLParams = 5
+const sizeParamIndex = 3
+const countParamIndex = 4
+const validNumberOfSizeParams = 2
+
+const (
+	invalidURL                    = "URL is not valid"
+	invalidNumberOfParamsError    = "Number of params not correct, expected /WIDTHxLENGTH/count"
+	invalidNumberOfSizeParamError = "Size not correct, expected /WIDTHxLENGTH/count"
+	invalidParamsType             = "Params should be numbers"
+)
+
+func errorResponse(w http.ResponseWriter, errType string) {
+	fmt.Fprintf(w, errType)
+}
+
+func diecutHandler(w http.ResponseWriter, r *http.Request) {
+	if params := strings.Split(r.URL.Path, "/"); len(params) == validNumberOfURLParams {
+		if size := strings.Split(params[sizeParamIndex], "x"); len(size) == validNumberOfSizeParams {
+			count := params[countParamIndex]
+
+			width, wOk := strconv.ParseInt(size[0], 10, 32)
+			height, hOk := strconv.ParseInt(size[1], 10, 32)
+			countNumber, cOk := strconv.ParseInt(count, 10, 32)
+
+			if wOk != nil || hOk != nil || cOk != nil {
+				errorResponse(w, invalidParamsType)
+			} else {
+				fmt.Fprintf(w, "%dx%d | %d", width, height, countNumber)
+
+			}
+
+		} else {
+			errorResponse(w, invalidNumberOfSizeParamError)
+		}
+	} else {
+		errorResponse(w, invalidNumberOfParamsError)
+	}
+}
+
+func defaultHandler(w http.ResponseWriter, r *http.Request) {
+	errorResponse(w, invalidURL)
+}
+
+func main() {
+	http.HandleFunc("/prices/diecut/", diecutHandler)
+	http.HandleFunc("/", defaultHandler)
+
+	fmt.Println("Server running on localhost:8080")
+	log.Fatal(http.ListenAndServe(":8080", nil))
+}